Snagging grinder



Sept. 15, 1953 s. E. coMsTocK, 3RD 2,651,838

SNAGGING GRINDER Filed May 15, 1952 2 Sheets-Sheet 1 m V /0 a INVENTOR.6ve 5 E COM57'0C/(3m Patented Sept. 15, 1953 new UNITED STATESFA'i'Ehi'l' @FFICE SNAGGING GRINDER George E. Comstock 3d, Holden,Mass., assignor to Norton Company, Worcester, Mass., a'corporation ofMassachusetts Application May 13, 1952, Serial No. 287,530

8 Claims. 1

The invention relates to snagging grinders. One object of the inventionis to provide a snagging grinder which can be operated with ttle effort.Another object is to provide a thoroughly safe snagging grinder. Anotherobject is to provide a snagging grinder of rugged yet simpleconstruction and which is versatile so that it can snag small or largebillets, short or elongated castings and can therefore be used for avariety of purposes in a steel plant or foundry. Another object of theinvention is to provide a snagging grinder capable of operating withhigher pressures between the grinding wheel and the work piece than havehitherto been achieved in actual practice. Another object is to providean economical grinder from the standpoint of grinding cost per unitvolume of work. Another obiect of the invention is to provide a poweroperated snagging grinder so arranged that the operators station isinternally of the area occupied by the machine whereby the grindingwheel may be driven to send the detritus away from the machine and adust collector systern for one or many machines can be installed tocollect the detritus without being in the way of the operator oroperators. Another object is to provide a snagging grinder of suchcharacteristics that it is movable along a track to produce the traversebetween grinding wheel and Work piece whereby several machines can beFigure 2 is an axial horizontal sectional view Figures 6 and '7 arefragmentary views illustrating modifications of the invention.

Referring first to Figures 1 and 3, secured in any suitable manner tothe floor In of the building where the grinder is located is a pair ofparallel rails H H forming a track. The rails II can be embedded in aconcrete floor and/or wooden ties can be used as in the case of arailroad track. A platform 12 constitutes the body of a car which runson the rails l I; heavy bearing brackets is are secured to the underside of the platform 52 and receive axle shafts l l on which are flangedwheels it: which rest upon the rails ll.

One of the axles "it has secured thereto a sprocket gear it which can bedriven by a chain extending from the gear 55 to a sprocket pinion 68driven by a fluid motor !9. This fluid motor is is reversible and issecured to a plate which is secured to one end of the platform i2.

Referring now to Figure l, a valve lever 2i a short portion 22 extendingat right angles to the upstanding part of the valve lever and the outerend of the short portion 22 is connected by a link 23 to a flange 2dprojecting from the cap 25 of a valve casing lit. A valve piston 2'3with three lands is movable in a bore in the casing 26 which the landssnugly fit. The valve casing 2% has a pressure channel 28 a pair ofexhaust channels 2t. 1' provide four duplicate valve casings '25 withthe same moving parts and channels and these are aligned and boltedtogether with bolts 3! Each valve casing 2% has a pair of channels 3!and 32 for sending oil to and receiving oil from the piece of apparatuswhich the particular valve controls. Referring now to Figures 1 and 3, Iprovide a tank 33 which contains a supply or" oil which is the hydraulicfluid to actuate the apparatus. 011 the cover of the tank 33 is a motor(i whose motor shaft is coupled to a pump 36.

The output side of the pump 36 is connected to piping which is connectedto all of the pressure channels 28 by being connected to one thereofthrough an end cap 33 since these pressure channels 28 are crossconnected to each other by a cross channel it which extends through eachvalve casing 25 and between them, suitable gaskets being provided toprevent leakage and the outer ends of the cross channel being blocked bythe end cap 38 and another end cap il at the other end of the set ofvalve casings 25. Exhaust piping t2 extends to the end cap ll and isconnected to a cross channel which cross channel 63 likewise extendsthrough each valve casing 26 and between them connecting all of theexhaust channels 29 together, and the same gaskets and the caps es andLi: prevent leakage. The piping 32 runs to the tank 33 to return thefluid thereto. In the piping 31 is a relief valve 49 the exhaust side ofwhich is connected to the tank 33 and thus the system can be set tocause each of the pieces of apparatus to exert just so much force and nomore. The intake side of the pump 36 is connected to the bottom of thetank 33 by means of piping 45.

The control apparatus has four valve levers, the valve lever 2! alreadyidentified and valve levers 52, 53 and 54; these are all alike and theirconnections to valve pistons corresponding to the valve piston 2'! areall alike, in fact Figure 4 could be a section through any of the valvecasings. Whenever any of the hand levers 2!, 52, 53 or 59 is moved tothe right, Figure 4., the channel 3! is connected to pressure and thechannel 92 is connected to exhaust.

The fluid motor I9, adapted to be operated by oil under pressure, isconnected by piping 58 to the channel 3| and by piping 51 to the channel32. When oil flows to the fluid motor i9 through the piping 58 andreturns from the motor I9 through the piping 5'I, which is when theoperator sitting upon the stool 89 draws the lever 2I towards him, themotor I9 revolves in such direction as to move the car to the operatorsleft which is to the right in Figure 3, conversely when the operatorpushes the valve lever 2I away from him, oil goes to the motor I9through the pipe 5! and leaves it through the pipe 56 and this causesthe car to move to the operators right, which is to the left in Figure3.

Referring to Figures 1 and 3, secured to the top of the platform I2 ofthe car is a base casting 63 having a massive central upstanding forkedportion 63 and. a pair of lateral upstanding forked portions 95. Withits lower end located in the forked portion 96 and connected thereto bya heavy rock shaft 99 is a large upstanding rocker 6? having a forkedtop 68. Extending through the forked top 88 and connected thereto by apin 99 is a horizontal overhead lever I0. A large depending lever II ofgenerally open box shape is connected by a pin I2 to the front of thelever 79, the pin 72 extending through and between the sides of thelever II and through the lever "59. A grinding wheel I5 is locatedbetween a pair of disc-like enlargements E6 of the bottom of the sidesof the lever II and is ournalled therein on an axle shaft TI to whichthe grinding wheel and also a double pulley I8 are secured.

Referring now to Figure 2, the disc-like enlargements it are connectedby integral peripheral connecting portions 79 which form with theenlargements I9 a Wheel guard for the grinding wheel l5 to keep thesparks and swarf from spraying upon the operator; the grinding wheel isintended to rotate clockwise as viewed in Figure 1 although because thestool 69 is not in line with the grinding wheel I5 that is to say iswell removed from the plane of rotation of the grinding wheel I5, thegrinding wheel could rotate counter-clockwise without great detrimentbut it is preferred not to have the swarf land upon the machine or anypart thereof.

Referring now to Figure 1, one of the sides of the lever II has anupwardly and rearwardly extending portion 89 while the opp osite side ofthe lever II has an upwardly and rearwardly extending offset portion 8Iand located between these portons 39 and 8| is a bored enlargement 82 ofa plate 83 and a pin 84 extends through the ends of the portions 80 andBI and through the bored enlargement 82 of the plate 89 thus pivotallymounting the plate 83 for movement up and down. Mounted on the plate 33and secured thereto by bolts 85 is an electric motor 88 having on itsarmature shaft 81 a double pulley 98 connected by belts 89 to the doublepulley "58. Of course the pulley 88 is keyed or otherwise fastened. tothe shaft 81, the pulley I8 is keyed or otherwise fastened to the axleshaft ll, and (see now Figure 2) a bushing 99 extending through the holein the grinding wheel :5 is keyed to the axle shaft 'I'I while a nut 9Imounted on the threaded end of the bushing 99 and the opposite flangedend of the bushing 99 grip the sides of the grinding wheel 15 so that itcan be driven by the rotation of the axle shaft ll, and as is customarysuitable blotters, not shown, are interposed between the side of thewheel and the nut Stand also between the side of the wheel and theflanged end of the bushing 99. Suitable bearings 92 and 93 are providedin the disclike enlargements 16 to journal the axle shaft l'l' and a nutand Washer 94 secures the pulley '58 to the axle shaft 11 which istapered at the end as shown. Thus whenever the motor 35 is energized,the grinding wheel 15 will be rotated, and I provide means to tightenthe belts 89 at will as follows.

Extending through a boss 95 at the front end of a forwardly extendingportion 96 of the lever II is a stud 91 having a vertically boredenlargement 98 in threaded engagement with a screw 99 passingtherethrough and the screw 99 has a reduced upper end I00 which extendsthrough a hole in the plate 83 and the reduced end I99 just fits thehole so that the resulting shoulder on the screw 99 can thrust the plate83 upwardly while a washer and cotter pin IIlI on the upper end of thescrew 99 serves to hold the parts from disengagement. By turning thescrew 99 to raise it the belts 89 are tightened.

On the rear end of the lever I9 is a rearwardly extending forkedenlargement I95 receiving the enlarged end I06 of a piston rod I01 Whosepiston, not shown, is located in a cylinder I99 having a head III] withan integral shaft III extending therefrom, the shaft I I I having on thelower end thereof an enlargement I I2. The rocker 61 has a rearwardlyextending forked portion H3 receiving the enlargement II2 through whichand through the forked portion extends a pin Il thus articulating thecylinder I09 to the forked portion II3. Similarly the piston rod I9! isarticulated to the rearwardly extending forked enlargement I05 by meansof a pin II5 extending through the enlargement I05 and the enlarged endI06.

Between the upwardly and rearwardly extending portion 80 and. the boredenlargement 82 is an enlarged end II8 of a piston rod II9 having apiston, not shown, in a cylinder I2! having a head I22 with an integralshaft I23 extending therefrom, the shaft I23 having an enlarged end I24located in the rearwardly extending forked enlargement I05 and connectedthereto by a pin I25 passing through the forked enlargement I95 and theenlarged end I24. Thus the cylinder I2I is articulated to the forkedenlargement I95 while the piston rod I I9 is articulated to the portion89 of the lever II.

The rocker 61 has on each side thereof a pair of laterally extendingintegral parallel flanges I39, each pair receiving the enlarged end I 3Iof a piston rod I32 having a piston, not shown, in a cylinder I34 havinga head I 35 with an integral shaft flanges its are articulated toth'e'pistoirro'ds I3 2 and the cylinders forked portions 55. v

Referring now to Figure 5, the several channels 3| and 32 aredifferentiated by the identification, below each pair, of one of thevalve levers 2!, 52, 53 and 54. The channel 3! of the valve controlledby the lever 52 is connected to piping I4! I34 are articulated to theand the channel 32 of the same valve is connected to piping M2. Thepiping MI is connected to hoses M3 and M4; the hose M3 is connected tothe bottom of the left hand cylinder I34 (Figure 3) and the hose Hi l isconnected to the top of the right hand cylinder [3d (Figure 3). Thepiping M2 is connected to hoses M5 and M6; the hose IE5 is connected tothe top of the left hand cylinder I3 5 while the hose M5 is connectedto' the bottom of the right hand cylinder I35.

The channel 3| of the valve controlled by the lever 53 is connected topiping i5! and the channel 32 of the same valve is connected to piping52. The piping I5] is connected to a hose which is connected to the topof the cylinder while the piping I52 is connected to a hose 55% which isconnected to the bottom of the cylinder W9.

The channel SI of the valve controlled by the lever 54 is connected topiping l6! and the channel 32 of the same valve is connected to pipingE62. The piping [Si is connected to a hose iSi which is connected to thefront end of the cylinder lZl while the piping M2 is'connected to a hoseHid which is conn cted to the front end of the cylinder I2 I,

The motor 3 1 is energized by a cable llli while the motor 8t isenergized by a cable ill. The cable ill and parts of the piping I5],152, [Bi and lti. are carried by a vertical support it. extendingupwardly from the car platform i2 This support H2 has a rearwardextension lit supporting a hose H5 which receives both cables lit andii! and extends to a swivel support i'it mounted on a stanchion Illsecured to the floor it}. Because the hose H5 is much longer than thedistance between the extension [l3 and the swivel support H6 when. theformer is right opposite the stanchion l'il, the car can move quite adistance along the rails it without breaking the hose H5 or the cableslit and iii therein. The operator of course has available switchescontrolling the stopping and starting of the mo tor but it has not beendeemed necessary to illustrate these.

it will now be seen that with the hand lever M the operator can move thecar to a position to grind any part of the billet or steel plate orwhatever it is that needs to be ground along the length thereof, that bymeans of the hand lever E2 the operator can tilt the rocker 6? which isan inverted pendulum to tilt the grinding wheel 15 in order to use thecorner thereof to dig deep into the metal, that by means of the handlever 53 the operator can raise and lower the grinding wheel and bymeans of the hand lever 54 he can move it towards and away from the car.The work piece, of course, will be supported on any suitable supportextending parallel to the track 6 H, II. It will be noted that the rockshaft is at about a convenient level for the work piece whereby thegrinding wheel can be tilted without any corresponding up or downmovement.

When the operator draws the lever 2: towards him the rocker or pendulum6i swings to the right, Figure 3, and when he pushes the lever 52 awayfrom him the rocker or pendulum 6'! swings to the left, Figure 3. Whenthe operator draws the hand lever 53 towards him, the grinding wheel '15rises and when he pushes the lever 55 away from him the grinding wheeli5 descends. When the grinding wheel contacts the work piece it pressesagainst it with a force governed by the setting of the relief valve is.This relief valve can have a hand wheel, lever or knob to set thepressure since adjustable relief valves are well known. However it willbe noted that the weight of the motor 86, the wei "it of the dependinglever H and most of the wei it of the overhead lever are added to thefind pressure force. When the operator draws the hand lever 5 towardshiin the grinding wheel '55 moves forward and when he pushes the handlever 54 away from him the grinding wheel "it moves toward the rear ofthe machine. These statements are made on the basis of the connectionsas shown but it will readily be understood that the connections can bereversed wherever and whenever desired and that includes the piping 56and El to operate the motor H9.

The valve pistons 2'? are normally maintained in neutral position bymeans of a device well known for such purpose consisting of a pair ofwashers 89 and till with an interposed spring 5&2, the assembly beingheld on a reduced end portion of the piston 2? by a nut M33 and thewasher therefore contacting a shoulder of the piston 2?. The Washer98:"? cannot rise above the position shown in Figure 4- on account of ashoulder in the casing 25 while the wash r ifil cannot descend below theposition shown in Figure l by reason of a shoulder in a cap It will beseen whenever a valve piston is in the neutral or central position asshown in Figure 4, the fluid is locked in the cylinder or cylindersoperated by the valve or, in case of the motor it, no fluid will flowthrough the motor. This feature is of importance especially in the caseof the cylinders 53 because when the operator releases the hand lever.22 the inverted pendulum ii'i is held wherever he has put it. It is ofimportance also in the case of the cylinder 525 because the fluid lockedin this cylinder holds the depending lever ll against the thrust of thegrinding wheel. By means of the hand lever 53 controlling the cylinderHi5 the opera-tor can cause the grindin wheel is to press against thework piece with the combined forces due to the pull of gravity on theoverhead masses and the fluid pressure, or he can hold the grindingwheel at a fixed level by releasing the hand lever 53. Furthermore sincethere is a slight arcuate motion to the grinding wheel produced byoperation of the cylinder iZi, the operator can use this arcuate motionas a fine downfeed.

It may be desired for some operations to allow the overhead weights togive the grinding pressure and to provide power means merely to lift thegrinding wheel at will. In this aspect of the invention the pins lid andHi; can be connected by power mechanism which will pull but not push asfor instance by substituting a chain for the integral shaft i l i. Thismodification is illustrated in Figure 6 in which the chain is numbered190. A further modification is illustrated in Fig'- ure 7 in which thehead H and the pin H4 are connected by a spring ISI. This modificationhas the following advantage: if the grinding wheel 15 is on the workpiece and the operator works the hand lever 53 so that the spring I9] isrelaxed, the grinding pressure equals the pull of gravity on the entiremass carried by the overhead lever 10 with, of course, due allowance formasses to the right of the pin 69. Now if the operator moves the lever53 to admit a little fluid through the hose [53 to shorten theconnection, the spring 19! will be flexed somewhat thus creating a forcewhich is subtracted from the total gravitational force thus diminishingsomewhat the pressure between the grinding wheel and the work piece andthe operator can continue to diminish this force until it reaches zeroand eventually the grinding wheel is raised. Thus, in the embodiment ofFigure 7, the operator can adjust the grinding pressure and this is aconsiderable advantage for lots of snagging operations.

It will thus be seen that there has been provided by this inventionsnagging grinders in which the various objects hereinabove set forthtogether with many thoroughly practical advantages are successfullyachieved. As many possible embodiments may be made of the aboveinvention and as many changes might be made in the embodiment above setforth it is to be understood that all matter hereinbefore set forth orshown in the accompanying drawings is to be interpreted as illustrativeand not in a limiting sense.

I claim:

1. A snagging grinder comprising a rock shaft, an inverted pendulummounted on said rock shaft, an overhead lever articulated to saidinverted pendulum at a point well above said rock shaft said overheadlever extending in a horizontal direction well away from said invertedpendulum, a depending lever articulated to said overhead lever at apoint well removed from the point of articulation of said overhead leverin said horizontal direction, a grinding wheel shaft mounted in saiddepending lever at a point well below its articulation to said overheadlever, whereby a grinding wheel on said shaft can be tilted by movingsaid inverted pendulum, said grinding wheel can be raised or lowered bymoving said overhead lever and said grinding wheel can be movedforwardly and rearwardly by moving said dependin lever, power means tomove said overhead lever to raise the grinding wheel, and power means tomove and to hold said depending lever.

2. A snagging grinder according to claim 1 in which the power means tomove the overhead lever is also adapted to move it to press the grindingwheel downwardly and to hold it at any position in which it is put.

3. A snagging grinder comprising a car, power means to move said car, aninverted pendulum mounted on said car, power means to move and to holdsaid inverted pendulum, an overhead lever articulated to said invertedpendulum at a point well above said car said overhead lever extending ina horizontal direction well away from said inverted pendulum, adepending lever articulated to said overhead lever at a point wellremoved from the point of articulation of said overhead lever in saidhorizontal direction, a grinding wheel shaft mounted in said dependinglever at a point well below its articulation to said overhead lever,power means to move and to hold said inverted pendulum, power means tomove said overhead lever to raise the grinding wheel shaft, and powermeans to move and to hold said depending lever.

4. A snagging grinder as claimed in claim 3 in which said power means tomove said overhead lever is also adapted to move it to press downwardlythe grinding wheel shaft and to hold said overhead lever at any positionin which it is put.

5. A snagging grinder as claimed in claim 4 having a motor mounted onsaid depending lever at a position remote from said grinding wheelshaft, a pulley on said motor, a pulley on said wheel shaft mounted insaid depending lever at a pulleys.

6. A snagging grinder as claimed in claim 3 having a motor mounted onsaid depending lever at a position remote from said grinding wheelshaft, a pulley on said motor, a pulley on said grinding wheel shaft anda belt connecting said pulleys.

7. A snagging grinder as claimed in claim 1 having power means to moveand to hold said inverted pendulum, and having spring means coupled tothe power means to move said overhead lever to raise the grinding wheelwhereby the weight of the depending lever can be counteracted to avarying amount by the power means and the spring means to producevarying grinding pressures.

8. A snagging grinder as claimed in claim '7 having a motor mounted onsaid depending lever at a position remote from said grinding wheelshaft, a pulley on said motor, a pulley on said grinding wheel shaft,and a belt connecting said pulleys, whereby the Weight of the motor isadded to that of the depending lever to produce grinding pressure andthe grinding pressure can be counter-acted to a varying amount by thepower means and the spring means to produce varying grinding pressures.

GEORGE E. COMSTOCK 31).

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,308,933 Cavicchi July 8, 1919 2,073,400 Cumming Mar. 9, 19372,137,140 Lewis Nov. 15, 1938 2,308,843 Wilson Jan. 19, 1943 2,559,295Grossenbacher July 3, 1951 2,569,291 Davis 1 Sept. 25, 1951

